Answer: 13
Step-by-step explanation: The mean of a data set is equal to the sum of the set of numbers divided by how many numbers are in the set.
So to find the mean of the data set shown here, let's begin by adding the numbers. So we have 12 + 15 + 10 + 12 + 21 + 9 + 12. This will be divided by how many numbers are in the set which is 7.
[tex]So[/tex] [tex]we[/tex] [tex]have[/tex] [tex]\frac{12 + 15 + 10 + 12 + 21 + 9 + 12}{7}[/tex]
Adding the numbers, we get 91.
91 is divided by how many numbers are in the set of 7.
91 divided by 7 is equal to 12.
So the mean of the set of data shown here is 13.
